Il 16/10/2012 08:23, Kuniyasu Suzaki ha scritto: >>> "delvm" is a command to delete a snapshot image in a qcow2 file. >>> However it does not reduce the qcow2 file size. >> >> Note that the file will not grow when new allocations are performed in >> the future. > > You mean that the qcow2 file size will not increase when "savevm" > commnad is issued after "delvm". > Namely, the qcow2 file size is almost same when I take a snapshot > after delete previous snapshot image.
Exactly. The first writes to the qcow2 file will also reuse the space left free by "delvm", if they have to allocate new clusters. >> QEMU should also convert the unused clusters to "holes" in the file >> system, but it doesn't do that yet. > > I hope a qcow2 file is reduced automatically when a snapshot is deleted. Yes, that's part of the plan. The file would not reduce its size, but the space would still be given back to the filesystem. Paolo
